green maple leaves; maple before turning red
Refers to fresh green maple leaves in spring and summer, or the tree itself before autumn coloring. A seasonal word (kigo) for early summer.
It's the season when the green maple leaves are beautiful.
Green maple trees are growing thickly in the temple garden.
kasane color combination (green front, russet back)
A traditional layered color scheme used in Heian-era court clothing, where the outer layer is green and the inner layer is russet, evoking maple leaves before they turn red. Specialized historical term.
See also: 重ね
The aomomiji kasane has a green front and a reddish back.
襲 is the general term for layered color combinations in traditional court dress; 青紅葉 is one specific named combination.
Compound of 青 (ao, 'green') and 紅葉 (momiji, 'maple leaves' or 'autumn colors'). The reading あおもみじ follows standard rendaku voicing.